1. Technical Field
A technique disclosed in the present specification is a technique relating to a printer, and specifically to a method for generating a color system conversion table for converting a coordinate value between a device dependent color space and a device independent color space.
2. Related Art
In order to obtain an appropriate printed material in accordance with the characteristic of individual printers, the characteristic of a print medium, the color development characteristic of ink, and the like, a A2B table (a table for conversion from a device dependent color space to a device independent color space) and a B2A table (a table for conversion from the device independent color space to the device dependent color space) are used. For example, when the B2A table is a Lab-CMYK table, an input color system is three dimensional, and an output color system is four dimensional, and therefore, an output value with respect to an input value is not uniquely determined. Thus, a technique for determining an output value (CMYK value) with respect to an input value (Lab value) by using an expression for conversion from a CMY color system to a CMYK color system is proposed (see, for example, JP-A-3-158071, JP-A-2011-254224).
The conversion from the CMY color system to the CMYK color system is non-linear, and therefore, according to the technique described in JP-A-3-158071, a large number of lattice points of the CMY color system are provided to secure the color reproduction accuracy, which requires time for calculation. Moreover, according to the technique described in JP-A-2011-254224, the expression for conversion from the CMY color system to the CMYK color system is used to generate a color chart expressed by coordinate values of the CMYK color system, and a result of the colorimetry is used to generate a B2A table. In this case, since a user generates color chart data, perform printing, and measures a colorimetric value each time expression for conversion from the CMY color system to the CMYK color system is changed, man-hours and time are needed.